What class is most sought in groups currently ?

iss sws/dominator/prophet are all in really good state atm.
sws with survivability (you want to be able to survive as much as possible as iss), dominator with cele cancels, and prophet with reuse on skills.

i would still pick sws above all if you're pvp oriented player. seems like overall stronger, extra permanent defensive stats and small ud on around 4 minute cooldown with wizard/good necklace. if you're not top geared, i think it's the class to pick